• 정보보호학회논문지
• /
• 제32권1호
• /
• pp.1-9
• /
• 2022

Fixslicing AES는 Bitsliced AES의 선형 계층에서 많은 Cycle이 발생하는 것을 최소화하기 위해 Shiftrows 단계를 생략한 기법으로 Bitsliced 기법 대비 30% 성능 향상을 보여준다. 하지만 생략된 Shiftrows를 보완하기 위해 코드량이 증가되기 때문에 Shiftrows를 절반만 생략한 Semi-Fixsliced와 완전히 생략한 Fully-Fixsliced로 나뉜다. 본 논문에서는 사전 연산 테이블 기법을 활용한 RISC-V 상에서의 Fixslicing AES의 CTR 모드 구현을 제안한다. CTR 모드의 특징을 활용하여 2-라운드 SubBytes 연산까지의 사전 연산을 통해 암호화 과정에서 2-라운드 SubBytes까지 생략한 빠른 암호화가 가능하다. 해당 기법을 활용하여 32-bit RISC-V 상에서 Semi-Fixsliced는 하나의 블록을 암호화하는 비용은 1,345 Cycle이며 기존 대비 7%의 성능 향상, Fully-Fixsliced는 1,283 Cycle 이며 기존 대비 9%의 성능 향상을 확인하였다.

• Tribology and Lubricants
• /
• 제37권6호
• /
• pp.224-231
• /
• 2021

Recently, the waterproofing performance of high-voltage connectors in automotive vehicles has attracted increased interest. In this study, an optimal cross-sectional shape was derived to obtain uniform contact pressure and strain by considering stress relaxation problems caused by initial tension when mounting a seal. A high strain of 52.1 was distributed in the round region, owing to excessive initial tension. The finite element method (FEM) analysis indicated that the strain corresponding to the optimal initial tensile was 11. We adopted six design factors to optimize the seal cross-section and three factors as the main design factors. An orthogonal arrangement table was prepared using Minitab. FEM analyses of 16 study models were conducted to determine the optimized model. The contact pressure of the optimization model is the most evenly distributed while satisfying the waterproof performance of 0.47 MPa. Compared to the initial model, the difference in strain decreases from 35.5% to 19.6%. Finally, the derived cross-sectional shape can reduce the strain of the round region by 33.8% and the differences in the contact pressure at the upper and lower surfaces by 42% and 76%, respectively.

• 비파괴검사학회지
• /
• 제29권5호
• /
• pp.421-426
• /
• 2009

열화상 카메라와 대상물의 측정 위치에 따른 방사각도에 따라 방사율은 달라지게 된다. 이로 인해 열화상 시스템을 이용한 온도 측정시 나타나는 온도 분포는 절대적 온도로 볼 수 없다. 대상체의 실제 표면 온도가 일정하더라도 열화상 카메라로 측정된 온도는 방사율 값에 따라 오차를 가지게 된다. 본 논문에서는 동일 온도로 가열된 원통 형태를 가지는 대상체와 평면 형태를 가지는 대상체의 온도를 열화상 카메라를 이용하여 측정하였다. 측정된 표면 온도값을 통하여 화각에 의한 방사율 보정표와 방사각도의 영향에 의한 반사율 보정식을 구하였으며 이를 바탕으로 측정 온도의 오차보정을 수행하였다. 그리고 방사 각도와 화각에 따른 온도 영향을 원자력 배관의 결함 검출에 적용하여 더욱 신뢰성 있는 표면 온도값을 획득하였다.

• 한국정보통신학회논문지
• /
• 제11권7호
• /
• pp.1332-1340
• /
• 2007

본 논문에서는 휴대인터넷 와이브로 (WiBro) 시스템의 보안계층 중 암호 키 (Traffic Encryption Key; TEK)를 암호 복호하는 key wrap/unwrap 알고리듬의 효율적인 하드웨어 설계에 대해 기술한다. 설계된 key wrap/unwrap 코어 (WB_KeyWuW)는 AES (Advanced Encryption Standard) 알고리듬을 기반으로 하고 있으며, 128비트의 TEK를 128비트의 KEK (Key Encryption Key)로 암호화하여 192비트의 암호화된 키를 생성하고, 192비트의 암호화된 키를 복호화하여 128비트의 TEK로 복호하는 기능을 수행한다. 효율적인 하드웨어 구현을 위해 라운드 변환 블록에 하드웨어 공유기법을 적용하여 설계하였으며, 또한 하드웨어 복잡도에 가장 큰 영향을 미치는 SubByte/InvSubByte 블록을 체 변환 방법을 적용하여 구현하였다. 이를 통해, LUT (Lookup Table)로 구현하는 방식에 비해 약 25%의 게이트 수를 감소시켰다. Verilog-HDL로 설계된 WB_KeyWuW 코어는 약 14,300개의 게이트로 구현되었으며, 100-MHz@3.3-V의 클록으로 동작하여 $16{\sim}22-Mbps$의 성능이 예상되어 와이브로 시스템 보안용 하드웨어 구현을 위한 IP로 사용될 수 있다.

• 동아시아식생활학회지
• /
• 제1권2호
• /
• pp.175-183
• /
• 1991

To examine the Royal evening party in the Man Kyoung Jeon, the authors studied“Jin Chan Eui Gue”, which is a historical record published in 1887(King Go-Jong) The results obtained from the study were as follows. 1. The dining tables were divided into two : fixed arranging tables(7) and taking-away tables. 2. There were no distribution of food and flowers to the attendants in the evening party. 3. Tables used in the evening party were all round tables. 4. According to the status or class of the attendant, the pattern or size of table settings were differentiated in the kinds of food, hights of food, flowers china ware etc. 5. All of the arrangements in the evening party were the same as those of the main party. 6. In the arrangements of tables for the King's Grand Mother, the hights of food on the dishes were as following levels, 1 dish : 9 chon(촌) 7 dishes : 7 chon(촌) 4 dishes : 6 chon(촌) 3 dishes : 5 chon(촌)

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집B
• /
• pp.288-293
• /
• 2001

A critical heat flux (CHF) prediction method using an artificial neural network (ANN) was evaluated for application to the high-heat-flux (HHF) subcooled flow boiling. The developed ANN predictions were compared with the experimental database consisting of a total of 3069 CHF data points. Also, the prediction performance by the ANN was compared with those by mechanistic models and a look up table technique. The parameter ranges of the experimental data are: $0.33{\leq}D{\leq}37.5mm$, $0.002{\leq}L{\leq}4m$, $0.37{\leq}G{\leq}134Mg/m^2s$, $0.1{\leq}P{\leq}20MPa$, $50\leq{\Delta}h_{sub,in}\leq1660kJ/kg$, and $1.1{\leq}q_{CHF}\leq276MW/m^2$. $276MW/m^2$. It was found that 91.5% of the total data points were predicted within $a{\pm}20%$ error band, which showed the best prediction performance among the existing CHF prediction methods considered.

• 기술혁신학회지
• /
• 제7권2호
• /
• pp.325-349
• /
• 2004

This paper tried to evaluate an economic analysis about research and development far areas of renewable resource in Korea. To evaluate this validity, we tried to calculate the spillover effect of R＆D investment through input-output table. In the first stage of spillover effect, we simply calculate the rate of return on R＆D investment for renewable energy resources in Korea through the input-output model, which can calculate the value added as well as output based upon the price of 2000 year. According to the first stage calculation, the rate of return on R＆B investment in solar heat is higher than any other renewable energy. In the second stage we tried to calculate the second round of spill over effect, which derives from the additional amount of supply of renewable resources due to the R＆D investment. The overall evaluation of R＆D invesment including the first stage as well as second stage spillover effect shows that bio-energy and waste energy generate 14 times as well as 2.5 times in the rate of return respectively.

• ETRI Journal
• /
• 제41권3호
• /
• pp.358-370
• /
• 2019

The main aim of this study is to select the optimal set of genes from microarray cancer datasets that contribute to the prediction of specific cancer types. This study proposes the enhancement of the feature selection filter algorithm based on Joe's normalized mutual information and its use for gene selection. The proposed algorithm is implemented and evaluated on seven benchmark microarray cancer datasets, namely, central nervous system, leukemia (binary), leukemia (3 class), leukemia (4 class), lymphoma, mixed lineage leukemia, and small round blue cell tumor, using five well-known classifiers, including the naive Bayes, radial basis function network, instance-based classifier, decision-based table, and decision tree. An average increase in the prediction accuracy of 5.1% is observed on all seven datasets averaged over all five classifiers. The average reduction in training time is 2.86 seconds. The performance of the proposed method is also compared with those of three other popular mutual information-based feature selection filters, namely, information gain, gain ratio, and symmetric uncertainty. The results are impressive when all five classifiers are used on all the datasets.

• 영어영문학
• /
• 제58권4호
• /
• pp.679-700
• /
• 2012

This study aims to examine Mark Twain's criticism of American capitalistic ideals in the late nineteenth century. During this second industrial revolution, industry showed rapid growth and capitalism established an order, while America suffered under the monopolization of capitalistic conglomerates. This resulted in the widening gap between the rich and the poor and the dehumanization caused by rapid industrialization. In A Connecticut Yankee in King Arthur's Court, Hank Morgan, the protagonist--who represents nineteenth-century America's industrialism, individualism, and capitalism--is sent back in time to the sixth century of Arthurian England. Hank attempts to introduce nineteenth-century technologies and machines to build a capitalistic system in the middle ages. However, Hank's efforts lead to disaster in which the country and civilization he worked to build is completely destroyed. Although Twain does not deny capitalistic ideals, he criticizes the "governmentality" that operates Hank's reform system to the extreme. Hank values efficiency and utilizes human beings as capital. Hank's economic reason not only transforms the Round-Table knights into speculators but also transforms their religious acts and abstract ideals into moneymaking businesses. The destructive ending anticipates the World Wars and the Great Depression in the first half of twentieth century and even serves to predict the dangers that follow.

• 한국수산과학회지
• /
• 제17권4호
• /
• pp.299-305
• /
• 1984

진주담치와 멸치를 보다 효율적으로 이용하기 위한 방안의 하나로서 진주담치와 시판 마른멸치를 건조하여 분말화한 후 조미료를 배합하여 건조분말 수우프를 만들었으며, 또한 이것을 적층필름용기(cellophane/polyester/aluminium foil/polyester: $20{\mu}m/15{\mu}m/7{\mu}m/20{\mu}m,\;13{\times}14cm$)에 함기포장하여 상온저장 중의 품질안정성을 검토하였다. 진주담치 및 마른 멸치를 건조분말화한 다음 이것에 설탕 $3\%$, 식염 $2\%$, 글루탐산나트륨 $5\%$, 마늘가루 및 후추가루 가가 $0.2\%$를 배합하는 것이 즉석 분말수우프로서 가장 좋은 배합비이었다. 분말수우프 제품의 수분활성은 진주담치의 경우 0.41, 마른멸치의 경우는 0.31 정도이었다. 진주담치제품의 총카로테노이드함량은 저장 중 약간 감소하였고, 휘발성염기질소와 아미노질소는 전제품이 저장 중 거의 변화가 없었으며, TBA 값은 저장 30일까지 약간 증가하다가 그 후 서서히 감소하는 경향을 나타내었다. 관능검사 결과 멸치분말수우프 및 진주담치분말수우프 제품은 모두 저장 100일동안 품질에 큰 변화가 없었으므로 즉석분말수우프로 이용가능하다는 결론을 얻었다.